syoo8

A couple of months ago I bought a rectangular analog clock (from Heinrich!) and it doesn't work. Any tips?

When it was initially installed, both ground contacts from the clock were connected to the car's ground, as well as the positive terminals for the clock's power and the backlighting. Four wires in play.

Result: The clock would only work when the lights (and thus, the backlighting) were on. The rest of the time, the clock stopped.

We changed the wiring so that only one ground contact from the clock was used. Three wires in play.

Result: For a week, the clock would work fine... until about an hour after the car was shut off. Then, the clock would stop.

Result #2: After the week elapsed, the clock started spooling forward (like when you press the + button to adjust the time) continuously. It did so unabated until i finally disconnected the clock.

I called VDO repair in California but they don't fix these things. Have any of you had this kind of a problem/know where I can fix my clock? Did I damage the clock by connecting both ground wires from the clock?

Thanks in advance,

Scott

Alan

There is only one ground wire - its Brown as usual.

The other wires should be:

Red - Battery (must be direct battery not a switched connection)
Black - Ignition feed on only with key in positions 2 & 3 (of 0-3)
Black/Blue - Variable illumination feed (on with markers and variable with rheostat)

You might want to try connecting it properly and seeing if the rubber setting button is disturbed (jammed on) for your fast advancing time issue... yes its possible you may have fried it...

But mainly it seems you have it wired incorrectly... why? you almost certainly have the Red wire connected to an illumination source or ignitions source.... and no permanent supply... the clock uses virtually no power and will run on its internal capacitor for a little while after power is lost.

If you aren't sure of connections ask first...

Just guessing at the cause here - but on a 928 Black is virtually never a ground on factory wiring....

Alan

Chuck Schreiber

Scott,

These guys are probably the best there is for any Porsche Gauge/Clock Repair.

http://www.nhspeedometer.com/

syoo8

Chuck-- thanks for the link to the clock repair!

Alan-- thank you so much for your detailed response!

The picture below is of the back of the clock.

Two black wires-- two ground wires that I connected accidentally. Now using just one of them, connected to brown ground wire from car.

Two red wires-- one for illumination, one for clock. I checked and I am quite sure that the illumination wire is connected to the illumination wire, the clock directly to the battery. I tested it several times.

White wire-- leaving it hanging.

I will check to see if the clock set button is stuck.

Any other thoughts?

Leon Speed

Hi Scott,

Here is a detailed write up how to change from a digital to an analog clock including the wiring: http://www3.sympatico.ca/mikeand.jan...k/clock_01.htm. You have a 5 wire connector for three pins, maybe it's better to attach the wires directly using the method described in the link?

Alan

Scott - (or H...) what did your clock come out of - the connector and wiring does not look like it attaches to a 928 (colors & number) see the connector pictures in the link for how the connector wiring should look - this is how mine looks - from memory. It exactly matched the wiring description I gave above as Mike's web write up does.

Alan

syoo8

Alan,

Heinrich made a wiring harness for the clock. I used it to connect the clock to the car. Top wire (black in the picture) to brown ground, 2nd from bottom red wire to switched 12V (for illumination), bottom red wire unswitched 12V (for clock.)

If we stipulate for a moment that I connected the clock correctly (which I believe I did, re-checking several times), then why did the clock shut off after an hour or so after the car was shut off? Does this mean that I have a deeper electrical problem lurking within the car?

Scott

Alan

Well try connecting the ignition feed - I don't see why that would affect your operation as you describe but its non-stock.

On your connector the white wire should go to a switched ignition feed. The second wire up should really go to the variable illumination (lights & rheostat) - not to just a simple ignition switched input (though that only affects when the lights come on - should do no harm).

Try that and see what happens - could just be the clock is busted.

If so I doubt it can be fixed, and especially doubt anyone will fix it for you... but you could always dissassemble and see whats going on? Nothing to loose at this point.

Alan